Smack: Fix wrong semantics in smk_access_entry() (5aa1de33) · Commits · e / devices / android_kernel_sony_msm8998

[ Upstream commit 6d14f5c7028eea70760df284057fe198ce7778dd ] In the smk_access_entry() function, if no matching rule is found in the rust_list, a negative error code will be used to perform bit operations with the MAY_ enumeration value. This is semantically wrong. This patch fixes this issue. Signed-off-by:

Tianjia Zhang <tianjia.zhang@linux.alibaba.com> Signed-off-by:

Casey Schaufler <casey@schaufler-ca.com> Signed-off-by:

Sasha Levin <sashal@kernel.org>

security/smack/smack_access.c

+8 −9

Original line number	Diff line number	Diff line
		@@ -90,17 +90,12 @@ int log_policy = SMACK_AUDIT_DENIED;
		int smk_access_entry(char subject_label, char object_label,
		struct list_head *rule_list)
		{
		int may = -ENOENT;
		struct smack_rule *srp;

		list_for_each_entry_rcu(srp, rule_list, list) {
		if (srp->smk_object->smk_known == object_label &&
		srp->smk_subject->smk_known == subject_label) {
		may = srp->smk_access;
		break;
		}
		}

		int may = srp->smk_access;
		/*
		* MAY_WRITE implies MAY_LOCK.
		*/
		@@ -108,6 +103,10 @@ int smk_access_entry(char subject_label, char object_label,
		may \|= MAY_LOCK;
		return may;
		}
		}

		return -ENOENT;
		}

		/**
		* smk_access - determine if a subject has a specific access to an object